1. Field of the Invention
The present invention relates to a structure of a vibration insulating member attached to be interposed between a vehicle-mounted fuel tank mounted on a vehicle body by a tank band for example and the vehicle body.
2. Related Art
Heretofore, a vehicle-mounted fuel tank is secured to a vehicle body by bolting a metallic tank band to a part of the vehicle body such as a cross member. Then, a vibration insulating member made of rubber is interposed between the fuel tank and the vehicle body to suppress noises and vibrations caused by waving fuel within the fuel tank from being transmitted to the vehicle body as disclosed in Japanese Patent Application Laid-Open No. 2006-192947A for example (paragraphs [0020] and [0022], FIGS. 1 through 4).
The vibration insulating member disclosed in JP2006-192947A is made of cushion rubber and absorbs, vibrations by fixing fourth and fifth projections formed on a lower face portion of the rubber to the fuel tank with an adhesive and by abutting first and second projections formed on an upper face portion of the rubber and having a split groove against a floor panel of the vehicle body.
Although such cushion rubber has had no problem in securing the fuel tank to the vehicle body by the band from the underneath of the tank after fixing the cushion rubber to the upper face of the tank because the cushion rubber is fixed to the fuel tank by means of the adhesive, the cushion rubber has had a problem that it readily falls away when a load in a shearing direction is applied.
The fuel tank is disposed between right and left side frames or between front and rear cross members by leaving predetermined gaps from them so that no vibration of the tank is transmitted to the vehicle body during traveling and no cushion rubber is attached to side surfaces of the tank in the front and rear and right and left directions. Therefore, although it has been possible to readily position the fuel tank in up and down directions (vertical direction) by the cushion rubber in mounting the fuel tank on the vehicle body, it has been difficult to position the fuel tank in terms of the front and rear and right and left directions of the vehicle body. It has also caused a problem that a capacity of the tank cannot be increased by narrowing the gaps between the tank and the side frames or the cross members in the front and rear and right and left directions.
Although it has been conceivable to provide the cushion rubber between the side surface of the tank and the vehicle body, the cushion rubber might possibly fall away in securing the tank if the cushion rubber is adhered on the side surface of the tank. It has been then conceivable to form the cushion rubber so that it engages with a fixing hole 210 as shown in FIG. 6. Because the hole is necessary in this case, a cushion rubber 100 is attached on the side of a vehicle body 200.
FIG. 6 is an enlarged section view showing a prior art structure of the vibration insulating member for attaching it to the fuel tank arranged in accordance to the concept described above.
The cushion rubber 100 shown in FIG. 6 is the vibration insulating member for the fuel tank that solves the aforementioned problem. The cushion rubber 100 having a seat portion 110 that butts a fuel tank 300 and an anchoring protrusion 120 that engages with the fixing hole 210 made through a securing region of the vehicle body 200 are formed into a single-piece by rubber, i.e., a soft material. A projection 130 that crimps the vehicle body 200 is formed around an outer periphery of the seat portion 110. The anchoring protrusion 120 is provided with an anchoring hook 140 that is anchored to an opening edge of the fixing hole 210.
The cushion rubber 100 constructed as described above is attached to the vehicle body 200 with the projection 130 crimping the surface of the attachment region of the vehicle body 200 and with the anchoring hook 140 butted and anchored to the opening edge of the fixing hole 210.
The vibration insulating member formed and attached as shown in FIG. 6 is readily deformed because the anchoring protrusion 120 that engages with the fixing hole 210 is formed integrally with the seat portion 110 that absorbs vibrations with the rubber, i.e., the soft material. Therefore, the attachment structure of the vibration insulating member has had a problem that anchoring force (removal bearing force) of the anchoring protrusion 120 for anchoring to the fixing hole 210 is small and the anchoring protrusion 120 falls away from the fixing hole 210 when the fuel tank 300 deforms or when external force in a lateral direction (thrust direction) is applied.
There has been also a problem that although hardening of the whole rubber may increase the anchoring force, it also increases insertion force required in inserting the anchoring protrusion and worsens workability and the vibration insulating quality of the vibration insulating member.
The prior art cushion rubber 100 has had also a problem that the cushion rubber cannot be utilized as a guide in mounting the fuel tank 300 because the force of the anchoring protrusion 120 for anchoring to the edge of the fixing hole 210 is weak and the cushion rubber 100 falls away in mounting the fuel tank 300 on the vehicle by utilizing the cushion rubber 100 as the guide.
Accordingly, in order to solve the aforementioned problems, the present invention seeks to provide a structure of a vibration insulating member that may be readily and firmly fixed to a vehicle body and may be used as a positioning member in mounting a fuel tank to a vehicle.